Indoor units (such as four-way cassette air-conditioning units) provided on the indoor side of known air-conditioning apparatuses or other like apparatuses include indoor heat exchangers and air-sending devices. The indoor heat exchangers are each provided therebelow with a drain pan that receives drain water condensed on the heat exchanger. The drain water received by the drain pan is discharged to the outside of the indoor unit through a drain pump and a drain pipe. In such a configuration, substances such as germs and mold in the air tend to fall into the drain water and to propagate therein. When germs and mold propagate, slime may be generated in the drain pan. The slime may lead to defective drainage such as generation of odor or clogging of the drain pipe. Hence, some indoor units include containers provided in the drain pans. The containers each contain an antimicrobial agent that suppresses the propagation of substances such as germs and mold. Since components of the antimicrobial agent in the container are dissolved into the drain water, an antimicrobial characteristic is imparted to the wet area. Thus, the propagation of substances such as germs and mold is suppressed (see Patent Literature 1, for example).